cdc.gov/coronavirus

Updates to the Evidence to 

Recommendation Framework: 

Pfizer-BioNTech and Moderna 

COVID-19 vaccine booster doses

Sara Oliver, MD, MSPH

ACIP Meeting

November 19, 2021
Evidence to Recommendations (EtR) Framework

2

Public 

Health 

Problem

Benefits 

and 

Harms

Values and 

Acceptability

Feasibility Resource 

Use

Equity
Evidence to Recommendations (EtR) Framework

3

▪ Previous presentations/discussions for booster doses of COVID-19 vaccines

September 23rd: 

COVID-19 vaccine booster doses: Benefit/risk discussion

Evidence to Recommendation Framework: Booster doses of Pfizer-BioNTech COVID-19 vaccine

VOTE: Pfizer-BioNTech COVID-19 booster doses 

https://www.cdc.gov/vaccines/acip/meetings/slides-2021-09-22-23.html

October 21st: 

National Institutes of Health: Mix and Match booster study

Evidence to Recommendation Framework: Booster doses of Moderna & Janssen COVID-19 vaccines

VOTE: Moderna & Janssen COVID-19 booster doses (including heterologous boosting)

https://www.cdc.gov/vaccines/acip/meetings/slides-2021-10-20-21.html
▪ Persons aged ≥18 years who received primary vaccination with Janssen 

COVID-19 vaccine should receive a single COVID-19 vaccine booster dose at 

least 2 months later

▪ Any FDA-approved or authorized COVID-19 vaccine (Pfizer-BioNTech, 

Moderna, or Janssen) can be used for booster dose, regardless of vaccine 

received for primary series

COVID-19 vaccine booster dose in persons who received 

a Janssen COVID-19 vaccine primary dose 
COVID-19 vaccine booster dose in persons who completed 

an mRNA primary series

Persons who should receive a COVID-19 

booster dose

• Aged ≥65 years 

• Aged ≥18 years and reside in long-term care 

settings

• Aged 50-64 years with certain underlying 

medical conditions

Persons who may receive a COVID-19 

booster dose, based on individual 

benefits and risks

• Aged 18-49 years with certain underlying 

medical conditions*

• Aged 18-64 years at increased risk for SARSCoV-2 exposure and transmission because 

of occupational or institutional setting

▪ Booster dose administered at least 6 months after completion of primary series

▪ Any FDA-approved or authorized COVID-19 vaccine (Pfizer-BioNTech, Moderna, or 

Janssen) can be used for booster dose, regardless of vaccine received for primary series

* Includes pregnant people 5
COVID-19 vaccine booster dose in persons who completed 

an mRNA primary series

Persons who should receive a COVID-19 

booster dose

• Aged ≥65 years 

• Aged ≥18 years and reside in long-term care 

settings

• Aged 50-64 years with certain underlying 

medical conditions

Persons who may receive a COVID-19 

booster dose, based on individual 

benefits and risks

• Aged 18-49 years with certain underlying 

medical conditions*

• Aged 18-64 years at increased risk for SARSCoV-2 exposure and transmission because 

of occupational or institutional setting

▪ Booster dose administered at least 6 months after completion of primary series

▪ Any FDA-approved or authorized COVID-19 vaccine (Pfizer-BioNTech, Moderna, or 

Janssen) can be used for booster dose, regardless of vaccine received for primary series

* Includes pregnant people 6
Policy Question

Persons who may receive a COVID-19 

booster dose, based on individual 

benefits and risks

• Aged 18-49 years with certain underlying 

medical conditions*

• Aged 18-64 years at increased risk for SARSCoV-2 exposure and transmission because 

of occupational or institutional setting

• All other persons aged ≥18 years 

7

All other persons ≥18 years of age 

may receive a COVID-19 booster dose 

≥6 months after completion of the 

mRNA primary series under the current 

Emergency Use Authorization

▪ Do the balance of benefits and risks and facilitation of implementation 

warrant an update to COVID-19 vaccine policy? 
8

Public 

Health 

Problem

Evidence to Recommendations Framework

Booster doses of COVID-19 vaccines
Trends in COVID-19 cases in the United States 

CDC. https://covid.cdc.gov/covid-data-tracker/#trends_dailycases. Accessed November 18, 2021

January 23, 2020 – November 16, 2021

9

47,244,379 total cases

7-day average: 

85,944 cases
Trends in COVID-19 hospitalizations in the United States 

CDC: https://covid.cdc.gov/covid-data-tracker/#new-hospital-admissions Accessed November 17, 2021

August 1, 2020 – November 15, 2021

10
US COVID-19 7-day case rate per 100,000

By state/territory

CDC: https://covid.cdc.gov/covid-data-tracker/#cases_casesper100klast7days Accessed November 18, 2021 11
Number of people fully vaccinated in the U.S. by COVID-19 

vaccine series type

CDC. https://covid.cdc.gov/covid-data-tracker/#vaccinations_vacc-people-onedose-pop-12yr. Accessed November 18, 2021 12

Over 195 million people fully 

vaccinated in the US

69% of the population ≥12 years of age 
0

2,000,000

4,000,000

6,000,000

8,000,000

10,000,000

12,000,000

14,000,000

16,000,000

2020-512020-522020-532021-012021-022021-032021-042021-052021-062021-072021-082021-092021-102021-112021-122021-132021-142021-152021-162021-172021-182021-192021-202021-212021-222021-232021-242021-252021-262021-272021-282021-292021-302021-312021-322021-332021-342021-352021-362021-372021-382021-392021-402021-412021-422021-432021-442021-452021-46

12-17 years 18-49 years 50-64 years 65+ years

COVID-19 vaccine first doses administered, by age group Number of first doses administered

Date of first doses administration (MMWR week)

Underreported

due to data lags

Source: Immunization Data Lake.

December 14, 2020 – November 15, 2021
VE against symptomatic infection by age group and time 

since vaccination in pre-Delta and Delta periods 

14

20-44 years 45-54 years 55-64 years 65+ years

PfizerBioNTech

Moderna

Pre-Delta (March 13–May 29) with 95% CIs in dotted lines

Delta (July 18–August 31) with 95% CIs in dotted lines

• VE is lower during Delta

• VE wanes during both periods 

• Curves similar across age groups

• For ≥65, VE lower than for other age groups soon after 

vaccination, no clear trend over time since vaccination The presented (fitted) curves are truncated on the day with ≤10 cases observed 

beyond it to avoid presenting wide confidence bounds.
Author, study platform, variant(s), outcome, age

Time since second dose VE % (95% CI)

Lin, North Carolina surveillance, Alpha & Delta, symptomatic disease, ≥12 years

2 months

7 months

95 (95-95)

70 (69-71)

Tartof, Kaiser Southern CA, Delta, any infection, ≥16 years

37-66 days

67-96 days 

97-126 days

127+ days

88 (81-92)

78 (70-83)

60 (48-69)

53 (39-65)

Tartof, Kaiser Southern CA, all variants, severe disease, ≥16 years

37-66 days

67-96 days 

97-126 days

127-156 days 

157+ days

89 (84-92)

92 (89-95)

93 (89-95)

91 (87-93)

88 (82-92)

Lin, North Carolina surveillance, Alpha & Delta, ≥12 years

2 months (hospitalization)

7 months (hospitalization)

2 months (death)

7 months (death)

96 (95-98)

88 (84-90)

96 (93-98)

88 (83-92)

Tenforde, IVY, Alpha & Delta, hospitalization, ≥18 years

14-120 days

120+ days

89 (85-92)

78 (73-82)

Vaccine effectiveness for Pfizer-BioNTech vaccine by time since second dose, outcome, and age

0 20 40 60 80 100

Vaccine Effectiveness (%)

Documented

or

symptomatic

infection

Severe disease,

hospitalization,

death

Feikin et al. in press at The Lancet and Tenforde et al in preparation
Author, study platform, variant(s), outcome, age

Time since second dose VE % (95% CI)

Lin, North Carolina surveillance, Alpha & Delta, symptomatic disease, ≥12 years

2 months

7 months

95 (95-95)

70 (69-71)

Tartof, Kaiser Southern CA, Delta, any infection, ≥16 years

37-66 days

67-96 days 

97-126 days

127+ days

88 (81-92)

78 (70-83)

60 (48-69)

53 (39-65)

Tartof, Kaiser Southern CA, all variants, severe disease, ≥16 years

37-66 days

67-96 days 

97-126 days

127-156 days 

157+ days

89 (84-92)

92 (89-95)

93 (89-95)

91 (87-93)

88 (82-92)

Lin, North Carolina surveillance, Alpha & Delta, ≥12 years

2 months (hospitalization)

7 months (hospitalization)

2 months (death)

7 months (death)

96 (95-98)

88 (84-90)

96 (93-98)

88 (83-92)

Tenforde, IVY, Alpha & Delta, hospitalization, ≥18 years

14-120 days

120+ days

89 (85-92)

78 (73-82)

Vaccine effectiveness for Pfizer-BioNTech vaccine by time since second dose, outcome, and age

Documented

or

symptomatic

infection

Severe disease,

hospitalization,

death

0 20 40 60 80 100

Feikin et al. in press at The Lancet and Tenforde et al in preparation Vaccine Effectiveness (%)
Author, study platform, variant(s), outcome, age

Time since second dose VE % (95% CI)

Lin, North Carolina surveillance, Alpha & Delta, symptomatic disease, ≥12 years

2 months

7 months

95 (95-95)

70 (69-71)

Tartof, Kaiser Southern CA, Delta, any infection, ≥16 years

37-66 days

67-96 days 

97-126 days

127+ days

88 (81-92)

78 (70-83)

60 (48-69)

53 (39-65)

Tartof, Kaiser Southern CA, all variants, severe disease, ≥16 years

37-66 days

67-96 days 

97-126 days

127-156 days 

157+ days

89 (84-92)

92 (89-95)

93 (89-95)

91 (87-93)

88 (82-92)

Lin, North Carolina surveillance, Alpha & Delta, ≥12 years

2 months (hospitalization)

7 months (hospitalization)

2 months (death)

7 months (death)

96 (95-98)

88 (84-90)

96 (93-98)

88 (83-92)

Tenforde, IVY, Alpha & Delta, hospitalization, ≥18 years

14-120 days

120+ days

89 (85-92)

78 (73-82)

Vaccine effectiveness for Pfizer-BioNTech vaccine by time since second dose, outcome, and age

Documented

or

symptomatic

infection

Severe disease,

hospitalization,

death

0 20 40 60 80 100

Feikin et al. in press at The Lancet and Tenforde et al in preparation Vaccine Effectiveness (%)
Author, study platform, variant(s), outcome, age

Time since second dose VE % (95% CI)

Lin, North Carolina surveillance, Alpha & Delta, symptomatic disease, ≥12 years

2 months

7 months

96 (96-96)

82 (81-87)

Bruxvoort, Kaiser Southern CA, Delta, any infection, ≥16 years

14-69 days

61-90 days

91-120 days

121-150 days

151-180 days

94 (91-96)

89 (85-92)

86 (81-90)

77 (69-83)

80 (70-87)

Lin, North Carolina surveillance, Alpha & Delta, ≥12 years

2 months (hospitalization)

7 months (hospitalization)

2 months (death)

7 months (death)

98 (96-98)

92 (90-94)

96 (92-98)

97 (90-96)

Tenforde, IVY, Alpha & Delta, hospitalization, ≥18 years

14-120 days

120+ days

92 (88-94)

88 (84-91)

Vaccine effectiveness for Moderna vaccine by time since second dose, outcome, and age

0 20 40 60 80 100

Vaccine Effectiveness (%)

Documented

or

symptomatic

infection

Severe disease,

hospitalization,

death

Feikin et al. in press at The Lancet and Tenforde et al in preparation
Summary

▪ Over 195 million people are fully vaccinated in the United States

▪ COVID-19 cases are increasing in some jurisdictions recently

▪ VE after primary series waning for infection, but protection remains high for 

severe disease and hospitalization

– Waning appears to be less pronounced for Moderna COVID-19 vaccine, compared to 

Pfizer-BioNTech COVID-19 vaccine recipients

19
Benefits 

and 

Harms

Evidence to Recommendations Framework

Booster doses of COVID-19 vaccines

20
21

PICO Question

Pfizer-BioNTech Moderna

Population Persons aged ≥18 years who completed a COVID-19 vaccine primary series ≥6 

months ago

Intervention Pfizer-BioNTech COVID-19 Vaccine 

booster dose (BNT162b2, 30 μg, IM)

Moderna COVID-19 Vaccine

booster dose (mRNA-1273, 50 μg, IM)

Comparison No booster dose

Outcomes Symptomatic laboratory-confirmed COVID-19*

Hospitalization due to COVID-19*

Death due to COVID-19

Transmission of SARS-CoV-2 infection

Serious adverse events*

Reactogenicity

* Critical outcomes
Updated Pfizer-BioNTech booster data

Clinical trial data requested by CDC.

▪ Phase 3 booster dose randomized control trial (RCT)

▪ ~10,000 participants from phase 2/3 efficacy trial

– All participants received 2-dose primary series of Pfizer-BioNTech COVID-19 vaccine 

▪ Pfizer-BioNTech booster dose and placebo doses randomized 1:1

– Randomization was stratified by age

• 60% 16-55 years

• 40% >55 years

– Booster doses given 10-12 months after second dose

▪ Median follow-up of 2.5 months post booster dose
Outcome 1: Symptomatic laboratory-confirmed SARS-CoV-2 

infection

Clinical trial data requested by CDC.

Population Events/Vaccine

(n/N)

Events/Placebo

(n/N)

Relative vaccine efficacy 

(95% CI)

Primary Outcome

No evidence of prior infection,

≥7 days post booster

6/4659 123/4614 95.2% (89.3%, 97.9%)

Secondary Outcomes

± evidence of prior infection,

≥7 days post booster

7/4994 124/4963 94.5% (88.3%, 97.4%)

All available efficacy (± evidence

of prior infection, post booster)

15/5003 141/4943 89.8% (82.6%, 94.0%)

0-7 days post booster 8/5003 15/4943 47.4% (-24.0%, 77.7%)

≥7 days to <2 months post booster 6/4995 112/4928 94.9% (88.5%, 97.8%)

≥2 months to <4 months post booster 1/4891 14/4616 93.3% (48.9%, 99.1%)
Outcome 1: Symptomatic laboratory-confirmed SARS-CoV-2 

infection

Clinical trial data requested by CDC.

Population Events/Vaccine

(n/N)

Events/Placebo

(n/N)

Relative vaccine efficacy 

(95% CI)

Primary Outcome

No evidence of prior infection,

≥7 days post booster

6/4659 123/4614 95.2% (89.3%, 97.9%)

Secondary Outcomes

± evidence of prior infection,

≥7 days post booster

7/4994 124/4963 94.5% (88.3%, 97.4%)

All available efficacy (± evidence

of prior infection, post booster)

15/5003 141/4943 89.8% (82.6%, 94.0%)

0-7 days post booster 8/5003 15/4943 47.4% (-24.0%, 77.7%)

≥7 days to <2 months post booster 6/4995 112/4928 94.9% (88.5%, 97.8%)

≥2 months to <4 months post booster 1/4891 14/4616 93.3% (48.9%, 99.1%)
Evaluation of other beneficial outcomes

Clinical trial data requested by CDC.

▪ Hospitalization due to COVID-19

– No hospitalizations due to COVID-19 occurred in the booster (3-dose) 

or placebo (2-dose) groups

▪ Death due to COVID-19

– No deaths due to COVID-19 occurred in the booster (3-dose) 

or placebo (2-dose) groups

▪ Transmission of SARS-CoV-2 infection

– No data to assess this outcome
Outcome 6: Serious Adverse Events

Study/populationa Events/Vaccine 

(n/N)

% SAE

Vaccine

Events/Placebo

(n/N)

% SAE

Placebo

Associated 

with 

vaccinationb

Pfizer/BioNTech, 

unpublished

16/5055 0.3 24/5020c 0.5 3

a. Included all randomized participants who received a booster dose

b. Three serious adverse events among booster recipients were deemed by blinded investigators to be related to 

vaccination. These included: moderate persistent tachycardia, moderate transient elevated hepatic enzymes, and 

mild elevated hepatic enzymes. 

c. There was one death among placebo recipients and none among booster dose recipients
Adverse events of clinical interest

Clinical trial data requested by CDC. 27

▪ No cases of anaphylaxis, hypersensitivity, or myocarditis/pericarditis reported 

– Given the rarity of these adverse events, we would not expect to capture them in a 

RCT of this size

▪ Lymphadenopathy was more common after the 3rd dose (2.7%) than after the 

primary series (0.4%)

– Typically mild to moderate and located in the axilla or cervical nodes

– Most occurred 1-3 days post booster and resolved within 1-3 days of onset

– Frequency higher in younger participants and female participants
▪ No updated data from phase 3 booster trial

Outcome 7: Reactogenicity 
Pfizer-BioNTech booster ≥6 months after primary series

Changes to GRADE from previous booster discussion

OutcomeImportance Previous evidence

certainty

Current evidence 

certainty

Benefits

Symptomatic laboratory-confirmed COVID-19Critical Very low High

Hospitalization due to COVID-19Critical Very low Very low

Death due to COVID-19 Important No data No data

Transmission of SARS-CoV-2 infection Important No data No data

Harms

Serious adverse eventsCritical Very low Low

Reactogenicity Important Very low Very Low

29
Myocarditis in Israel

Reported after Pfizer-BioNTech COVID-19 vaccine, December 2020-October 10, 2021

As reported by Israel at FDA’s VRBPAC meeting. Slides here: https://www.fda.gov/media/153086/download . 30

Age 

(years)

Post-dose 1 

Rate per 100,000

Post-dose 2

Rate per 100,000

Post-dose 3

Rate per 100,000

Number of 3rd

dose delivered

Females

12-15 0 0.6 0 279

16-19 0 0.9 0 97,807

20-24 0.4 2.5 0 141,910

25-29 0 0.4 0 130,283

≥30 0.1 0.3 0 1,542,142

Males

12-15 0.5 6.6 0 292

16-19 1.2 16.1 5.2 96,238

20-24 2.2 10.3 3.6 139,015

25-29 1.2 8.4 0.7 133,650

≥30 0.5 1.7 0.4 1,448,745

Rates of myocarditis after a third dose appear to fall between rates seen after dose 1 and dose 2
114

298

488

2000 1500 1000 500 0

31

7

2

0

0

0 500 1000 1500 2000

Benefits and risks after Pfizer-BioNTech COVID-19 booster dose

18-29

30-49

50-64

≥65

Age groups 

(years)

Cases of Myocarditis

Expected per Million Doses

COVID-19-Associated Hospitalizations

Prevented per Million Doses

Scenario:

• VE for hospitalization averaged from four platforms1

• Boost to 95% VE for hospitalization

• Myocarditis risk equivalent to risk after 1st and 2nd dose averaged

2080

1. Scobie et al., COVID-NET, VISION, IVY Network

COVID-NET hospitalization rates from the week of August 21, 2021; Myocarditis rates from VAERS data through August 18, 2021

Age Group VE for 

hospitalization

18 – 29 years 90.7%

30 – 49 years 90.2%

50 – 64 years 91.1%

≥65 years 85.1%

For every million doses of vaccine given 

Females: 1 case of myocarditis

Males: 13 cases of myocarditis
Benefits and risks after Pfizer-BioNTech COVID-19 

booster dose

▪ Phase 3 RCT booster efficacy data demonstrates booster dose provides 

additional protection and is safe 

– No hospitalized cases of COVID-19 after 2-dose primary series

▪ Based on data from Israel, myocarditis risk after booster dose of Pfizer-BioNTech 

COVID-19 vaccine appears to fall between rates seen after dose 1 and dose 2

32
33

Moderna booster data

No booster vaccine efficacy/effectiveness studies identified

Moderna booster study previously presented*

Part A: Phase 2 randomized, observer-blind, placebo-controlled dose confirmation 

study among participants aged ≥18 years 

Part B: study amended for open label phase based on participant selection

Placebo recipients → 100 μg primary series

50 μg primary series → 50 μg booster (≥6 months after dose 2)

100 μg primary series → 50 μg booster (≥6 months after dose 2)

Immunobridging to patients in Phase 3 efficacy study

Prespecified non-inferiority analysis 

28 days after booster versus 28 days after dose 2 of primary series

*Unpublished data obtained from the study sponsor: https://www.cdc.gov/vaccines/acip/meetings/downloads/slides-2021-10-20-21/02-COVID-Miller-508.pdf
Moderna booster data

▪ Symptomatic laboratory-confirmed COVID-19

– Geometric mean titers of booster recipients (N=149) compared to primary series 

recipients (N=1,053)

– The geometric mean ratio of 1.76 (95%CI: 1.50–2.06) met non-inferiority criteria

▪ Serious Adverse Events

– No SAEs occurred among the 171 participants receiving a 50 ug booster in the open 

label booster study within 28 days of the booster dose

▪ Reactogenicity

– Severe reactogenicity occurred among 10.8% of participants receiving a booster in 

the open label booster study 

34
Moderna booster ≥6 months after primary series

Summary of GRADE – No update to previous discussion

35

OutcomeImportance Evidence certainty

Benefits

Symptomatic laboratory-confirmed COVID-19Critical Very low

Hospitalization due to COVID-19Critical No data

Death due to COVID-19 Important No data

Transmission of SARS-CoV-2 infection Important No data

Harms

Serious adverse eventsCritical Very low

Reactogenicity Important Very low
Benefits and risks after Moderna COVID-19 booster dose

▪ No phase 3 RCT booster efficacy data available for Moderna

– Immunogenicity study demonstrates the ability to boost antibody levels 

▪ Effectiveness after a primary series appears to have waned less in Moderna

than in Pfizer

▪ Myocarditis risk after booster dose of Moderna is unknown

– Accumulating evidence from multiple sources suggests a higher risk for myocarditis 

following Moderna compared to Pfizer-BioNTech primary series vaccination

– Moderna booster dose is a lower dose (50μg) than the primary series dose (100μg) 

36
Number needed to vaccinate with booster dose to prevent 

one hospitalization over 6 months

37

11994

3636

859

8738

3361

2051

481

0

2000

4000

6000

8000

10000

12000

14000

18-29 30-49 50-64 65+

Number needed to vaccinate to prevent one 

hospitalization

Age groups (years)

Moderna

Pfizer-BioNTech

** Not estimable due to pre-booster efficacy estimated at >95%

**
Number needed to vaccinate with booster dose to prevent 

one infection over 6 months

38

81

58

102

133

56 55

71

85

0

20

40

60

80

100

120

140

18-29 30-49 50-64 65+

Number needed to vaccinate to prevent one 

infection

Age groups (years)

Moderna

Pfizer-BioNTech
Summary of safety surveillance findings

▪ V-safe

– For Pfizer-BioNTech and Moderna, local and systemic reactions were reported less 

frequently following a booster dose than dose 2 of the primary series

– Moderna booster appears to be more reactogenic than Pfizer-BioNTech booster, 

regardless of the primary series manufacturer

▪ VAERS

– Most reports (≥93%) were non-serious (similar to primary series)

– Most frequently reported non-serious AEs were known and well characterized AEs 

associated with COVID-19 vaccination

– 54 preliminary reports of myocarditis

• 12 verified reports that met CDC case definition

39
Impact of a booster dose on transmission

▪ After a primary mRNA COVID-19 vaccine series, protection against asymptomatic 

infection (and presumably transmission) was found for a time period1,2

– Largest impact seen in the first 2 months post-vaccination2

– Likely an impact of very high antibody titers 

▪ Limited data on impact of booster dose on asymptomatic infection/transmission

– One study from Israel found lower viral loads in patients with breakthrough infections after 

a booster dose, similar to viral loads seen within 2 months after primary series2

– Early VE against SARS-CoV-2 infection after a booster dose demonstrates increase in VE 

(including asymptomatic infection)3,4

▪ While protection against asymptomatic infection may not be permanent, even 

temporary protection may favor into benefit/risk balance approaching winter and 

holidays with increased travel and indoor gatherings

40

1CDC Science Brief https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html 2Levine-Tiefenbrun et al. Nature Medicine 2021 https://www.nature.com/articles/s41591-021-01575-4

3Saciuk et al. Journal of Infectious Diseases https://academic.oup.com/jid/advance-article/doi/10.1093/infdis/jiab556/6415586

4Andrews et al. Effectiveness of BNT162b2 (Comirnaty, Pfizer-BioNTech) COVID-19 booster vaccine against covid-19 related symptoms in England: test negative case-control study | medRxiv
Summary

Balance of benefits and harms for booster doses 

▪ Booster dose of Pfizer-BioNTech COVID-19 vaccine is effective in preventing 

laboratory confirmed symptomatic SARS-CoV-2

▪ Data from Moderna trial does not provide efficacy data, but demonstrates the 

ability to boost immune response

▪ Individual benefit/risk balance for booster doses of an mRNA vaccine varies by age 

– Older adults have the clearest benefit/risk balance

– Among other ages, variation within balance of benefits and risks

– Myocarditis data after booster doses reassuring to date

▪ Unable to account for other benefits

– Possible impact on rates of community transmission

41
42

Values and 

Acceptability

Evidence to Recommendations Framework

Booster doses of COVID-19 vaccines
▪ Survey respondents were asked:

– “Have you personally received a booster or additional dose of the COVID-19 vaccine after you 

were already fully vaccinated?” 

– 4 in 10 fully vaccinated adults are unsure whether they are eligible for a 

booster dose 

Survey of fully vaccinated adults (vaccine booster eligibility)

KFF COVID-19 Vaccine Monitor (October 14-24, 2021) KFF COVID-19 Vaccine Monitor: October 2021 | KFF
▪ Survey respondents were asked:

– “Which comes closer to your view about the news that some people might need vaccine boosters?”

– More than 6 in 10 adults overall say the news that some people might need 

boosters “shows that scientists are continuing to find ways to make vaccines 

more effective.” 

Vaccine booster confidence 

KFF COVID-19 Vaccine Monitor (September 13-22, 2021) KFF COVID-19 Vaccine Monitor: September 2021 | KFF
45

Feasibility 

and 

Implementation

Evidence to Recommendations Framework

Booster doses of COVID-19 vaccines
Number of people with a booster dose in the U.S. by COVID-19 

vaccine series type

CDC. https://covid.cdc.gov/covid-data-tracker/#vaccinations_vacc-people-onedose-pop-12yr. Accessed November 18, 2021 46

Over 31 million people have 

received a booster dose in the US
Booster dose 

recommendation

Expanded booster 

recommendation

0

5

10

15

20

25

30

35

0

200

400

600

800

1000

1200

8/138/168/198/228/258/288/31

9/39/69/9

9/129/159/189/219/249/279/3010/310/610/9

10/1210/1510/1810/2110/2410/2710/30

11/211/511/8

11/1111/14

Daily number of booster doses administered, by manufacturer 

Persons ≥18 years of age Cumulative Additional 

Daily Additional Doses (K) Doses Administered (M) 11/8/2021

Underreported

due to data lags

Note: Number of people who received a booster dose includes anyone who is fully vaccinated and has received another dose of COVID-19 vaccine starting August 13, 2021. This

includes people who received booster doses and people who received additional doses.

Source: Immunization Data Lake. Data as of November 16, 2021, 0600AM.

Total Booster Doses Administered by Manufacturer to 

Date

Manufacturer Total Booster Number

Pfizer 18,296,085

Moderna 12,011,138 

Janssen 354,121 

Other 13,206 

Cumulative (All) 30,674,550 
48

▪ At least 31 million individuals in the United States have received a 

COVID-19 vaccine booster dose

▪ ~17 million individuals ≥65 years of age received a COVID-19 booster dose

▪ Some states currently broadening booster eligibility criteria 

Implementation of COVID-19 vaccine booster doses
49

▪ Vaccine recommendations based on risk and exposures are more difficult to 

implement than age-based recommendations

▪ ACIP recommendations that are consistent with the FDA EUA are easier to 

communicate and implement 

▪ If recommendations for booster doses varied across the two mRNA vaccines, 

it would be difficult to communicate and implement

Implementation of COVID-19 vaccine booster doses

Considerations
50

Equity

Evidence to Recommendations Framework

Booster doses of COVID-19 vaccines
Percentage of people who have received at least one dose 

of the COVID-19 vaccine by race/ethnicity over time

CDC. https://covid.cdc.gov/covid-data-tracker/#vaccination-demographics-trends as of November 16, 2021, and US Census Bureau National Population Estimates

0

10

20

30

40

50

60

70

Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21 Jul-21 Aug-21 Sep-21 Oct-21 Nov-21

AI/AN

Asian

Black

Hispanic/Latino

NHOPI

White

51
Booster doses in persons ≥18 years of age with completed 

vaccination series ≥6 months earlier* by race/ethnicity

Data from 27,085,156 people with booster doses

Race/ethnicity was available for 18,832,653 (69.5%) people with a booster dose

Notes: *Includes Janssen booster doses for people who have completed a primary vaccination series >= 2 months earlier. Number of people who received a booster dose includes anyone who is fully vaccinated and has received another

dose of COVID-19 vaccine starting August 13, 2021. This includes people who received booster doses and people who received additional doses. The expected timing for a booster dose was set at >=6 months after primary series

completion. Primary series is determined by the vaccine type of the second mRNA dose received or the first J&J/Janssen dose received. Does not include vaccine administrations reported by Texas as the primary series cannot be linked to

booster dose in the aggregate format submitted by Texas. Source: Immunization Data Lake. Data as of November 16, 2021, 0600AM.

23.4%

24.6%

15.8%

17.9%

16.3%

16.8%

12.9%

76.6%

75.4%

84.2%

82.1%

83.7%

83.2%

87.1%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Booster dose received when series complete >= 6 months ago No booster dose received when series complete >= 6 months ago

Hispanic/Latino

N=1,355,230

American Indian/Alaska Native, Non-Hispanic

N=134,060

Asian, Non-Hispanic

N=815,801

Black, Non-Hispanic

N=1,351,030

Native Hawaiian/Other Pacific Islander, Non-Hispanic

N=36,595

White, Non-Hispanic

N=14,302,149

Multiple/Other, Non-Hispanic

N=837,788
Summary - Equity

▪ Some disparities in primary series vaccine delivery have improved over time

▪ Early data on COVID-19 booster doses demonstrates disparities by race and 

ethnicity

– Recommendations that are complex, difficult to communicate, or difficult to 

implement may worsen disparities in booster vaccination rates 

53
Summary 
Work Group Interpretation 

▪ Top priority should be continued vaccination of unvaccinated individuals

▪ Balance of benefits and risks varies by age

– Older adults have the clearest benefit/risk balance

– Myocarditis data after booster doses reassuring to date, continue to closely monitor

– Increases in COVID-19 cases may also impact benefit/risk balance

Goals of COVID-19 vaccines:

▪ Primary goal: Prevention of severe disease 

▪ Secondary goals: 

Maintaining workforce and healthcare capacity

Reduce infection and transmission

▪ Unknown impact of COVID-19 vaccine booster dose on prevention of transmission. 

However, even reduction in transmission may be important around winter and holidays 

55
56

Evidence to Recommendations Framework

Type of 

recommendation

We do not recommend the 

intervention

We recommend the 

intervention for individuals 

based on assessment of 

benefits and risks

We recommend the 

intervention 

Used when the risks

clearly outweigh the 

benefits

Used when the 

benefits clearly 

outweigh the risks 

Used when there is 

diversity of the 

benefits and risks 

Can allow flexibility

across a population
57

Evidence to Recommendations Framework

Type of 

recommendation

We do not recommend the 

intervention

We recommend the 

intervention for individuals 

based on assessment of 

benefits and risks

We recommend the 

intervention 

Used when the risks

clearly outweigh the 

benefits

Used when the 

benefits clearly 

outweigh the risks 

Used when there is 

diversity of the 

benefits and risks 

Can allow flexibility

across a population

SHOULD

receive a booster

MAY

receive a booster
Individual benefit-risk considerations for people who may

receive a booster dose 

▪ Potential benefits of booster dose

– Reduced risk of SARS-CoV-2 infection, severe disease

– May reduce transmission of SARS-CoV-2 to others 

▪ Potential risks of booster dose

– Rare risks of serious adverse events (e.g., myocarditis, pericarditis, TTS, GBS, anaphylaxis)

– Common risks of transient local and systemic symptoms

▪ Individual risk factors for SARS-CoV-2 infection

– Risk of exposure (occupational and institutional settings, e.g., healthcare workers, long term care settings)

– Risk for infection (time since completion of primary series)

▪ Individual impacts of SARS-CoV-2 infection

– Risk for severe infection (related to underlying conditions)

– Risk associated with a person’s circumstances (living with/caring for at-risk individuals or consequences of 

inability to meet obligations due to infection)

CDC https://www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html 58
Updates for the future 

▪ Updates from a Moderna COVID-19 booster dose

▪ Rates of myocarditis after 3rd dose 

▪ Updated data for overall safety profile of booster doses

▪ Continued evaluations for vaccine effectiveness

– Includes VE for primary series and booster doses

59
60

Current recommendations for booster doses of COVID-19 vaccines

Age

mRNA COVID-19 vaccine primary series Janssen 

COVID-19 

vaccine 

primary series

No risk factors

Occupational or 

institutional 

exposures

Underlying 

medical 

conditions

Resident of LTCF

≥65 

years

Should

receive a booster

Should

receive a booster

Should

receive a booster

50–64 

years

Not eligible May

receive a booster

Should

receive a booster

18–49 

years

May

receive a booster
61

Proposed recommendations for booster doses of COVID-19 vaccines

Age

mRNA COVID-19 vaccine primary series Janssen 

COVID-19 

vaccine 

primary series

No risk factors

Underlying 

medical 

conditions

Resident of LTCF

≥65 

years

Should

receive a booster

Should

receive a booster

Should

receive a booster

Should

receive a booster

50–64 

years

May

receive a booster

18–49 

years

May

receive a booster
Policy Question

Persons who may receive a COVID-19 booster 

dose, based on individual benefits and risks

• All other persons aged ≥18 years 

62

All other persons ≥18 years of age 

may receive a COVID-19 booster dose 

≥6 months after completion of the 

mRNA primary series under the current 

Emergency Use Authorization

▪ Do the balance of benefits and risks and facilitation of implementation 

warrant an update to COVID-19 vaccine policy? 

Persons who should receive a COVID-19 

booster dose

• Aged ≥65 years 

• Aged ≥18 years and reside in long-term care settings

• Aged 50-64 years with certain underlying medical 

conditions
63

Proposed recommendations for booster doses of COVID-19 vaccines

Age

mRNA COVID-19 vaccine primary series Janssen 

COVID-19 vaccine 

No risk factors primary series Resident of LTCF

≥65 

years

Should

receive a booster

Should

receive a booster

Should

receive a booster

50–64 

years

18–49 

years

May

receive a booster

Option #2
COVID-19 vaccine booster dose in persons who completed 

an mRNA primary series: PROPOSED, Option #2

Persons who should receive a COVID-19 

booster dose

Aged ≥50 years 

Aged ≥18 years residing in LTCF

Persons who may receive a COVID-19 

booster dose, based on individual 

benefits and risks

All other persons aged ≥18 years 

▪ Booster dose administered at least 6 months after completion of primary series

▪ Any FDA-approved or authorized COVID-19 vaccine (Pfizer-BioNTech, Moderna, or 

Janssen) can be used for booster dose, regardless of vaccine received for primary series

64
65

ACIP Vote

Interim Recommendation

A single COVID-19 vaccine booster dose is recommended for 

persons aged ≥18 years* who received an mRNA COVID-19 vaccine 

primary series based on individual benefit and risk, 

at least 6 months after the primary series, 

under the FDA’s Emergency Use Authorization

*Individuals ≥18 years of age not otherwise recommended to receive a COVID-19 vaccine 
66

ACIP Vote

Interim Recommendation

Option #2

A single COVID-19 vaccine booster dose is recommended for 

persons aged ≥50 years who received an mRNA COVID-19 vaccine,

at least 6 months after the primary series, 

under the FDA’s Emergency Use Authorization
▪ Monica Godfrey

▪ Megan Wallace

▪ Sarah Mbaeyi

▪ Rachel Gorowitz

▪ Jack Gersten

▪ Jefferson Jones

▪ Eddie Shanley

▪ Mary Chamberland

▪ Deblina Datta

▪ Stephen Hadler

▪ VTF ACIP WG Team

▪ ACIP COVID-19 Vaccines Work Group

▪ Vaccine Task Force

▪ Epi Task Force

▪ Respiratory Viruses Branch

Acknowledgments
For more information, contact CDC

1-800-CDC-INFO (232-4636)

TTY: 1-888-232-6348 www.cdc.gov

The findings and conclusions in this report are those of the authors and do not necessarily represent the 

official position of the Centers for Disease Control and Prevention.

Thank you